China's decision to set up a national security committee is meant to rattle the nerves of those who mean to harm it, the foreign ministry said Wednesday.

The ruling Communist Party announced the move in a communique at the end of a key four-day meeting to set the direction of reform for the next decade.

China is embroiled in a bitter territorial row with Japan over disputed islands in the East China Sea. It has also asserted its claims in the South China Sea more aggressively in recent months, while Washington has announced a foreign policy "pivot" towards Asia.

But foreign ministry spokesman Qin Gang focused more on domestic threats when asked about the new committee at a regular briefing.

"The establishment of the security committee will make forces like terrorism, separatism and extremism nervous," he added.

"In short, all the forces who want to threaten and sabotage China's national security forces will get nervous."

But he turned on the questioner, a reporter from the Japanese news agency Kyodo, asking him: "Are you going to compare Japan to those forces?"

The news of the security committee plan came two weeks after a fiery attack in Beijing's Tiananmen Square, and days after bomb blasts at a provincial Communist Party headquarters blamed on a lone citizen reportedly intending to "take revenge on society".

China's top security official Meng Jianzhu has described the East Turkestan Islamic Movement, a militant group seeking independence for the Xinjiang region, as a "behind-the-scenes" supporter of the Tiananmen attack.

"The purpose for China to establish the national security committee is to improve our national security regime and national security strategy so as to ensure the security of the nation," Qin said. He had no comment on its membership.

Bank of America Merrill Lynch analysts said the committee would probably be similar to the US National Security Council which is run by the White House.

"China's SSC will most likely be chaired by Xi Jinping," they wrote in a report, with key members probably including Premier Li Keqiang, the foreign minister and other officials.

The official Xinhua news agency cited the party communique as saying the committee will "improve systems and strategies to ensure national security".

"This will be a major change for China when it responds to emergencies involving state security in the future," Xinhua said in a separate commentary.

"It comes after a series of security challenges at home and abroad in recent years," it added, without elaborating.

The state-run China Daily newspaper quoted Li Wei, director of the anti-terrorism centre at the China Institutes of Contemporary International Relations, as saying the new body will probably have a high-level co-ordination role in the event of "a major emergency and incidents that pose threats to national security, such as border conflicts and major terrorist attacks".

But Chinese social media users were sceptical.

"Feeling extremely safe," posted one user of Sina Weibo, a Chinese version of Twitter.

"The KGB's full name is 'The Committee of State Security of the Soviet Union'", wrote another.